This invention relates to the field of PC Cards such as mass storage systems, particularly a solid state mass storage system or memory package known as a flash card. More particularly, this invention relates to a hermetically sealed flash card that is especially suitable for industrial applications where conditions of high humidity and wide temperature ranges are encountered.
PCMCIA Cards, or PC Cards, are add-on devices about the size of a credit card, in length and width, but thicker. PC Cards slide into PCMCIA slots in computers. PC Cards come in several thicknesses, depending on application, which include memory upgrades, modems, network connectors, or even hard disk drives. At present, PC Cards are known as Type I, Type II and Type III. These three cards all have 68 pin connectors at the end and are of the same length and width; but they differ in height or thickness. Type I cards generally contain software programs or extra memory. Type II cards typically house modems (e.g., data and fax) and network adapters. Type III cards are thick enough to accommodate removable hard disk drives and wireless communication devices. It is conceivable that in the future even thicker cards, i.e., Type IV and higher designations, may be introduced.
The term "flash card", "memory card", "PC Card" and "PCMCIA Card" will be used interchangeably herein. Flash card memory packages or mass storage systems currently exist which are compatible with PCMCIA standards. Such flash card units are available from Sundisk Corporation of Santa Clara, Calif. These existing flash card units from Sundisk have a plastic frame in which a memory card is retained. A plastic connector houses metallic pins which extend from the rear of the connector. The rearwardly facing pins are soldered directly to printed circuit lines on the memory card and the connector is loosely retained in notches in the frame. The frame and memory card are sandwiched between layers of insulating material and stainless steel outer covers on opposite sides of the frame and memory card. The stainless steel outer covers are bonded to the plastic frame by adhesive. The outer surface of the frame adjacent the connector has a keyway which complements a shoulder on the slot in the computer to ensure that the flash card is inserted in the right orientation. If an attempt is made to insert the card upside down, interference between the shoulder on the slot and the keyway structure on the card will prevent full insertion of the card into the slot.
While suitable for their intended purposes, some of the specifications for presently available flash cards make them inappropriate or unsuitable for industrial applications where high humidity environments and wide temperature ranges are encountered. In particular the present humidity specification for Sundisk flash cards is 8%-95%, non-condensing, for both operating and non-operating conditions, while the specification for temperature is 0.degree. C. to 65.degree. C. for operating conditions and -20.degree. C. to +85.degree. C. for non-operating conditions. Those specifications, particularly the humidity specification, limit the usefulness of the flash cards in certain industrial applications, and it is highly desirable to have a flash card with improved characteristics, especially in regard to humidity.
Also, a need has been identified to protect the connector pins of PC Cards from dirt and other contamination when not in use.